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Ga-67 citrate scintigraphy in the management of malignant lymphomas is well established. It cannot, however, differentiate malignant from benign lesions because this agent also accumulates in benign inflammatory lesions. The authors present a case of increased I-123 IMP uptake on both early and delayed SPECT images in a patient with malignant lymphoma of the central nervous system. Results show that I-123 IMP SPECT can help differentiate malignant lymphoma from benign lesions and other malignant brain tumors.

To evaluate the redistribution phenomenon on delayed 1-123 IMP SPECT images of children and adolescents with partial seizures, 25 patients were selected and investigated in the interictal state. Early and delayed SPECT were performed 15-20 minutes and 5 hours, respectively, after 1-123 IMP injection. Redistribution patterns were classified into three groups : 1) redistribution (RD) (-) group (n = 5), in which a low-uptake area on the early image persisted or was enlarged on the delayed image, 2) RD (+) group (n = 14), in which a low-uptake area on the early image changed to normal distribution on the delayed image, and 3) marked redistribution (MRD) (+) group (n = 6), in which a low-uptake area on the early image changed to a high uptake area on the delayed image. Among the patients who were followed for at least 12 months after the SPECT scans, the short-term clinical outcome tended to be good in the RD (+) group, intermediate in the MRD (+) group, and poor in the RD (-) group. These results of our preliminary comparative study indicate that the redistribution pattern of 1-123 IMP may be related to the clinical aspects in patients with partial seizures and that it may play an important role in predicting their short-term clinical outcome.

We report the case of a 25-year-old woman with systemic lupus erythematosus. She complained of headache and left hemiparesis and was admitted to our hospital. She was in a coma after admission. Brain MRI showed no abnormalities, but brain single photon emission computed tomography showed diffuse hyperperfusion in the right frontal and temporal lobes. The calculated measured regional cerebral blood flow in the right hemisphere was increased to 40 to 55 mL/100 g/min, and that in the left was within the normal range of 25 to 35 mL/100 g/min. Two months later, the hyperperfusion was disappeared. The hyperperfusion could be explained by inflammatory changes.

Forty-six epileptic patients with partial seizures and normal CT underwent 48 examinations of early and delayed SPECT using I-123 IMP in the interictal phase. One of them underwent a follow-up SPECT in a more stable state compared to the first SPECT. Another patient, with informed consent, underwent a follow-up SPECT in combination with pharmacologic activation with bemegride. Early SPECT was performed 30 minutes after an IMP injection and delayed SPECT 4 to 4 1/2 hours later. Temporal changes in uptake pattern were visually classified into six types and compared with known patterns of SPECT uptake in relation to ischemic, hyperemic, and other changes. These were also correlated with the amount of epileptic activity seen on the EEG.

I-123 IMP scintigraphy was performed on a 59-year-old man with malignant melanoma. The images showed diffuse uptake in the bone marrow. These findings were more evident when using I-123 IMP than with Ga-67 citrate. I-123 IMP does not normally concentrate in the bone marrow. I-123 IMP scintigraphy may be more sensitive and specific in evaluating the bone marrow metastases from a malignant melanoma.

I-123 iodoamphetamine (IMP) and Ga-67 scintigraphy of malignant melanoma were performed to compare the accumulation of these tracers regarding tumor diameter to determine the site of I-123 IMP accumulation and to evaluate the use of I-123 IMP and Ga-67 in postoperative follow-up. The studies involved 44 patients with a definite diagnosis of malignant melanoma during a 10-year period from April 1991 through March 2001. In this study a very high detection rate of 90.9% was obtained for primary foci with 1-123 IMP. With Ga-67, the primary site detection rate was 25%. The results suggest that 1-123 IMP is superior to Ga-67 with respect to the detection rate of primary site.

Radiation angiopathy was developed by the process of accelerated atherosclerosis at the site of irradiation. The case of a 44-year-old man with right hemiparesis showing a high signal intensity in the left semioval center on MRI and a defect in the left temporo-parietal area with subsequent filling-in with I-123 IMP brain SPECT is reported. Digital subtraction angiography showed typical radiation angiopathy with ulceration in the left common carotid artery. Twenty-four years previously, he underwent curative irradiation of a neck mass that revealed Hodgkin's disease by biopsy. The emboli formed at the site of radiation-induced angiopathy and caused cerebral infarction. The perfusion abnormality in the territory of the embolic artery was detected by I-123 IMP SPECT. Long-term survivors of neck irradiation are at high risk for the development of carotid arterial disease and should be watched carefully.

1-123 IMP is now widely used as a radioactive agent for cerebral blood flow scintigraphy. It is also known to accumulate in certain types of tumors. The authors present a case in which 1-123 IMP accumulated in peritoneal metastases of hepatocellular carcinoma.

In pulmonary disease, the clearance of N-isopropyl-p-[I-123] iodoamphetamine (I-123 IMP) from the lung is prolonged, and retention of the tracer is noted in the pulmonary lesion as a result of damage to the pulmonary endothelium. A patient with acute pulmonary thromboembolism was examined using I-123 IMP pulmonary SPECT. The patient was treated with heparin after the early images were obtained but before the delayed images. The early images showed mildly reduced distribution of the tracer in the right lower lobe. Delayed images showed no retantion of the tracer. The findings indicate that pulmonary endothelial cells in a transient, pulmonary arterial hypoperfused area may remain intact.

N-isopropyl-p-[I-123] iodoamphetamine (I-123 IMP) SPECT studies were performed on a 75-year-old patient who could be clinically classified as subcortical arteriosclerotic encephalopathy (Binswanger's disease). Regional cerebral blood flow (rCBF) was quantitatively measured by a microsphere model, and was diffusely decreased in the whole brain (mean rCBF: 36 ml/100 g/minute). After a ventriculoperitoneal shunt operation, his clinical symptoms were markedly improved, and the improvement was validated by a 32% increase of mean rCBF. However, MRI and CT images showed no significant interval changes before and after the shunt operation. Regional rCBF measurement by I-123 IMP SPECT should be performed and plays an important role in the evaluation of Binswanger's disease.

I-123 IMP is now widely used as a radioactive material for cerebral blood flow scintigraphy. It is also known that this substance will accumulate in certain types of tumors. The authors present a case of a 47-year-old woman who showed accumulation of I-123 IMP in hepatic cell adenoma. 6 refs., 3 figs.

A 52-year-old woman with normal mentation experienced slowly progressive muscle weakness an atrophy in lower limbs for seven months. She was diagnosed as amyotrophic lateral sclerosis with upper and lower motor neuron signs by neurological examination, EMG and muscle biopsy from the right biceps brachii muscle. Brain CT and MRI showed no adnormal densities. Three-Brain CT and MRI showed no abnormal densities

A 63-year-old woman with numbness of the fingers bilaterally underwent I-123 IMP SPECT and magnetic resonance imaging. On both early and delayed SPECT images with I-123 IMP, increased accumulation of I-123 IMP was noted in the posterior horn of the left lateral ventricle and in the white matter of the left parieto-occipital lobe. These areas were consistent with lesions of which the signal intensity approximates that of the normal gray matter on all pulse sequences. Thus, a focally increased accumulation in the white matter on both early and delayed SPECT images with I-123 IMP may reflect heterotopic gray matter

Ten patients with unusual uptake and retention of I-123 IMP in their brain tumors were studied. Of these ten patients, five had meningiomas and the remaining five had glioblastoma, malignant astrocytoma, malignant lymphoma, metastatic brain tumor, and cellular blue nevus. Six tumors (five meningiomas and the glioblastoma) showed short term retention of I-123 IMP. Three tumors (the malignant astrocytoma, the malignant lymphoma, and the metastatic brain tumor) showed a delayed increase of radioactivity and the cellular blue nevus showed a gradual increase and long term retention of the tracer.